Circular path generating device

ABSTRACT

A circular path generating device comprises a base, a sliding stage, a working portion, and a driving device. The sliding stage is movable on the base along a first axial direction while the working portion is movable on the sliding stage along a second axial direction. The driving device has a driving portion and a crank portion, wherein the driving portion is configured for driving the crank portion to rotate, and the crank portion is connected to the working portion. When the driving portion drives the crank portion to rotate, the working portion is driven by the crank portion to move along a circular path. Thus the circular path generating device according to the present invention advantageously owns a mechanism of one degree of freedom and a simple structure, is capable of performing uniform circular motions, and can be easily controlled.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a circular path generating device, and more particularly, to a circular path generating device utilizing bi-axial movement and characterized by a mechanism of one degree of freedom, a simple structure, uniform circular motion, and easy control, etc.

2. Description of Related Art

Mechanism of machines and/or polishers for grinding end surfaces of optical fiber ferrules has three types, namely the planetary gear mechanism, the linkage mechanism, and the eccentric mechanism.

Generally speaking, wafer grinding machines are functionally similar to those machines designed for grinding end surfaces of optical fiber ferrules. Both of them require a grinding platform, and are capable of repeated and circulative grinding. However, conventional optical fiber grinding machines and conventional wafer grinding machines also share the following drawbacks:

[1] Inevitable performing via a mechanism of two degrees of freedom: The first example of conventional mechanism designs for grinding end surfaces of optical fiber ferrules is disclosed, for example, in U.S. Pat. No. 6,428,391 B2, entitled “METHOD AND APPARATUS FOR POLISHING”, wherein grinding is effected by motions of the linkage mechanism driven by two driving input sources which are commonly controlled by one motor. Such grinding mechanism of two degrees of freedom needs belts to drive an additional crank, and therefore results in excessive complicity of the driving input sources.

[2] Complex (cam-linkage) mechanism: The second example of conventional mechanism designs for grinding end surfaces of optical fiber ferrules is disclosed, for example, in U.S. Pat. No. 6,454,631, entitled “POLISHING APPARATUS AND METHOD”, wherein two cams are configured for driving operations of an upper platform and a lower platform so as to generate intended grinding paths. Such grinding mechanism has two degrees of freedom and is not capable of functioning based on a single platform.

[3] Incapability of uniform circular motion: Another conventional mechanism design for grinding optical fiber patch cords is exemplified by Taiwan Patent No. 431258 (Patent Certificate No. 175358), entitled “MACHINE FOR GRINDING OPTICAL FIBER PATCH CORDS”, wherein the linkage mechanism thereof cannot generate uniform circular motion for grinding, and in consequence, the velocity thereof at every point varies entirely.

[4] Requirement of complicated control: The third example of conventional mechanism designs for grinding end surfaces of optical fiber ferrules is disclosed, for example, in U.S. Pat. No. 5,947,797, entitled “COMPUTER-CONTROLLED METHOD FOR POLISHING”, wherein X-direction plates and Y-direction plates are controlled by a programmed logic controller (PLC) to generate grinding motions along the desired paths, and yet such control is rather complicated.

Hence it is imperative to develop a novel method/mechanism to overcome the foregoing drawbacks.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a circular path generating device which employs a mechanism of one degree of freedom, features a simple structure, is capable of operating based on uniform circular motions, and can be easily controlled, etc., so as to overcome the drawbacks of the conventional designs such as complexity of driving input sources, complex mechanism, incapability of uniform circular motion, and requirement of complicated control.

The technical solution to the aforesaid problems according to the present invention is to provide a circular path generating device comprising:

a base having a first axial-direction rail portion;

a sliding stage having a first sliding portion and a second axial-direction rail portion, wherein the first sliding portion is slidably disposed on the first axial-direction rail portion so that the sliding stage is able to move along a first axial direction;

a working portion having a second sliding portion, a working surface, and a non-working surface, wherein the second sliding portion is slidably disposed on the second axial-direction rail portion so that the working portion is able to move along a second axial direction, and a central position of the non-working surface has a connecting portion; and

a driving device having a driving portion and a crank portion, wherein the driving portion is configured for driving the crank portion to rotate, and the crank portion is connected to the connecting portion.

Accordingly, through motions of the working portion along the second axial direction and motions of the sliding stage along the first axial direction, coordinates of the working portion can vary within a predetermined planar range. When the crank portion is driven by the driving portion to rotate, the working portion is driven by the crank portion to move along a circular path.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The invention will become more fully understood from the following detailed description and accompanying drawings, which are given for illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1 is a perspective view of a circular path generating device according to the present invention;

FIG. 2 is a side elevation view of the circular path generating device according to the present invention;

FIG. 3A schematically shows a first motion of the circular path generating device according to the present invention;

FIG. 3B schematically shows a second motion of the circular path generating device according to the present invention;

FIG. 3C schematically shows a third motion of the circular path generating device according to the present invention;

FIG. 3D schematically shows a fourth motion of the circular path generating device according to the present invention;

FIG. 4A schematically shows a first grinding direction of the circular path generating device according to the present invention;

FIG. 4B schematically shows a second grinding direction of the circular path generating device according to the present invention;

FIG. 4C schematically shows a third grinding direction of the circular path generating device according to the present invention;

FIG. 4D schematically shows a fourth grinding direction of the circular path generating device according to the present invention;

FIG. 5 schematically shows a moving process of the circular path generating device according to the present invention;

FIG. 6 schematically shows a moving path of the circular path generating device according to the present invention;

FIG. 7 is an exploded perspective view of a second embodiment of the circular path generating device according to the present invention; and

FIG. 8 is a sectional view of parts of a third embodiment of the circular path generating device according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.

Referring to FIG. 1 and FIG. 2, a circular path generating device according to the present invention includes a base 10, a sliding stage 20, a working portion 30, and a driving device 40.

The base 10 has a first axial-direction rail portion 11.

The sliding stage 20 has a first sliding portion 21 and a second axial-direction rail portion 22. The first sliding portion 21 is slidably disposed on the first axial-direction rail portion 11, thus allowing the sliding stage 20 to move along a first axial direction X.

The working portion 30 (e.g., a single-layer grinding plate) has a second sliding portion 31, a working surface 32, and a non-working surface 33. The second sliding portion 31 is slidably disposed on the second axial-direction rail portion 22, thus allowing the working portion 30 to move along a second axial direction Y. A central position of the non-working surface 33 has a connecting portion 331.

The driving device 40 has a driving portion 41 and a crank portion 42. The driving portion 41 is configured for driving the crank portion 42 to rotate. The crank portion 42 is connected to the connecting portion 331.

Accordingly, with the working portion 30 moving along the second axial direction Y, and the sliding stage 20 moving along the first axial direction X, coordinates of the working portion 30 can vary within a predetermined planar range. When the crank portion 42 is driven to rotate by the driving portion 41, the working portion 30 is driven by the crank portion 42 to move along a circular path.

Referring to FIG. 3A, assuming that the working portion 30 defines a reference point A, when the crank portion 42 moves the connecting portion 331 to a first position P1, the reference point A is located at a fifth position P5. Referring to FIG. 3B, when the crank portion 42 moves the connecting portion 331 from the first position P1 to a second position P2, the working portion 30 is driven to move along the second axial-direction rail portion 22 in the second axial direction Y by a predetermined distance S, and the sliding stage 20 is driven to move along the first axial-direction rail portion 11 in the first axial direction X by the predetermined distance S. In consequence, the reference point A is moved from the fifth position P5 to a sixth position P6. Referring to FIG. 3C, when the crank portion 42 moves the connecting portion 331 from the second position P2 to a third position P3, the working portion 30 is driven to move along the second axial-direction rail portion 22 in the second axial direction Y by the predetermined distance S, and the sliding stage 20 is driven to move along the first axial-direction rail portion 11 in the first axial direction X by the predetermined distance S, such that the reference point A is moved from the sixth position P6 to a seventh position P7. Referring to FIG. 3D, when the crank portion 42 moves the connecting portion 331 from the third position P3 to a fourth position P4, the working portion 30 is driven to move along the second axial-direction rail portion 22 in the second axial direction Y by the predetermined distance S, and the sliding stage 20 is driven to move along the first axial-direction rail portion 11 in the first axial direction X by the predetermined distance S. As a result, the reference point A is moved from the seventh position P7 to an eighth position P8.

FIG. 4A to FIG. 4D show variations of grinding directions of the working surface 32 when grinding a predetermined workpiece. While the connecting portion 331 is driven by the crank portion 42 to move from the first position P1 toward the second position P2, the grinding direction in which the predetermined workpiece is ground is shown in FIG. 4A. Similarly, FIGS. 4B to 4D show the grinding directions in which the predetermined workpiece is ground when the connecting portion 331 is driven by the crank portion 42 to move from the second position P2 toward the third position P3, from the third position P3 toward the fourth position P4, and from the fourth position P4 toward the first position P1, respectively.

It can be understood from the above descriptions and FIG. 5 that the crank portion 42, when driven by the driving portion 41, drives the working portion 30 to move as uniform circular motions (as illustrated in FIG. 6, which shows the moving path of the working portion 30).

With reference to FIG. 7, the driving device 40 further comprises a speed reducer 43. The speed reducer 43 has two ends which are disposed upon the driving portion 41 and the crank portion 42, respectively. The speed reducer 43 is driven by the driving portion 41 and in turn drives the crank portion 42 to rotate. In addition, the circular path generating device of the present invention is equipped with two ball bearings 50. One of the ball bearings 50 is disposed at the connecting position where the connecting portion 331 is connected to the crank portion 42, and the other of the ball bearings 50 is disposed at the connecting position where the driving portion 41 is connected to the speed reducer 43.

The present invention is applicable to various grinding machines, polishing machines, and other equipment for use in optical fiber and semiconductor manufacturing processes so as to enhance quality of optical-fiber-related and semiconductor-related products.

In the embodiment depicted in FIG. 7, the second sliding portion 31, the working surface 32, and the non-working surface 33 are separate parts assembled together to form the working portion 30. It is understood that the working portion 30 may also be integrally formed, as shown in FIG. 8, wherein a single workpiece is processed to form the second sliding portion 31, the working surface 32, and the non-working surface 33.

To sum up, the present invention has the following advantages and effects:

[1] Performing by a mechanism of one degree of freedom: As previously mentioned, some conventional mechanism designs for grinding end surfaces of optical fiber ferrules use a motor to control two driving input sources and drive related linkage mechanism to move. However, such grinding mechanisms of two degrees of freedom need belts to drive an additional crank, and as a result, driving input sources become much complicated. By contrast, the present invention utilizes the driving portion 41 to directly drive the crank portion 42, and therefore, is characterized by its simple driving input source design. The mechanism according to the present invention of one degree of freedom is apparently superior to conventional grinding mechanisms of two degrees of freedom.

[2] Simple structure: As previously mentioned, some conventional mechanism designs for grinding end surfaces of optical fiber ferrules are more structurally complicated because grinding paths thereof are generated by upper and lower platforms which are driven by two cams. In the present invention, however, a much simpler structure is employed in which the working portion 30 moves along a circular path simply by virtue of the crank portion 42 and accompanying sliding motions along the first and second axial directions X, Y.

[3] Capability of Uniform circular motion: As previously mentioned, the linkage mechanisms of some conventional mechanism designs for grinding optical fiber patch cords cannot contribute to uniform circular motions, thus rendering velocity of every point to be variable entirely. Nevertheless, the driving portion 41 of the present invention is a single driving output source and capable of contributing to uniform circular motions.

[4] Achievement of Easy control: As previously mentioned, some conventional mechanisms for grinding end surfaces of optical fiber ferrules require complicated control by using a PLC to control X-direction and Y-direction plates, and thereby generate grinding motions along desired paths. By contrast, the present invention takes advantage of the driving relationships among components and makes it possible to control forward and backward rotating motions simply by connecting the power source to related capacitors.

While the present invention is demonstrated herein with reference to the preferred embodiments, it is to be understood that the foregoing embodiments may be slightly modified or changed without departing from the spirit and scope of the present invention. 

1. A circular path generating device, comprising: a base having a first axial-direction rail portion; a sliding stage having a first sliding portion and a second axial-direction rail portion, the first sliding portion slidably disposed on the first axial-direction rail portion so as for the sliding stage to move along a first axial direction; a working portion having a second sliding portion, a working surface, and a non-working surface, the second sliding portion slidably disposed on the second axial-directional rail portion so as for the working portion to move along a second axial direction, wherein a central position of the non-working surface comprises a connecting portion; and a driving device having a driving portion and a crank portion, the driving portion configured for driving the crank portion to rotate, and the crank portion connected to the connecting portion; wherein motions of the working portion along the second axial direction and motions of the sliding stage along the first axial direction allow coordinates of the working portion to vary within a predetermined planar range, and when the crank portion is driven by the driving portion to rotate, the working portion is driven by the crank portion to move along a circular path.
 2. The circular path generating device of claim 1, wherein the driving device further comprises a speed reducer, two ends of the speed reducer are disposed upon the driving portion and the crank portion, respectively, and the speed reducer drives the crank portion to rotate when being driven by the driving portion.
 3. The circular path generating device of claim 2, further comprising two ball bearings, wherein one of said ball bearings is disposed at a connecting position where the connecting portion is connected to the crank portion, and the other of said ball bearings is disposed at a connecting position where the driving portion is connected to the speed reducer. 